| 摘要 |
PURPOSE: Provided is a method for controlling the molecular weight and/or molecular weight distribution of high cis-1,4-polybutadiene as it is polymerized from 1,3-butadiene in the presence of a rare earth catalyst in a gas phase process. CONSTITUTION: A method of controlling the molecular weight, molecular weight distribution or both of high cis-1,4-polybutadiene that is produced in a gas phase process from 1,3-butadiene in the presence of a rare earth metal containing catalyst, which method comprises adjusting at least one of: (a) the temperature of the polymerization; (b) the butadiene partial pressure; (c) the concentration of cocatalyst in the product in the reactor or alternatively, the ratio of the aluminum metal of the cocatalyst to the rare earth metal of the catalyst; (d) selection of cocatalyst; and (e) the residence time of the rare earth catalyst.
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